Fastlane
»
Holden Forums
»
Holden Technical Talk
»
HQ 72 - Electronic Distributor - Running a 'booster' from Starter to Coil + for better starting?
Rank: Newbie
Groups: Registered
Joined: 25/03/2025(UTC) Posts: 2 ![Australia]( "Australia") Location: Melbourne Thanks: 2 times
|
Hi Guys,
Looking for some expert Holden advice here...
I've had my beloved HQ 72 auto van running on LPG/petrol for 25 years, upgraded to a Commodore Electronic Distributor and Coil 20+ years ago :)
I installed a Relay back then to give full 12 volt from battery to coil, using original ignition wire as trigger only.
Started having issues starting in hot weather recently, some rough idle that I thought I had tuned out. Then got caught on the side of the road for some hours trying to work it out.
I found I had low voltage on the Starter solenoid and could only start by running 2 temp + wires:
1 - to starter solenoid solenoid + trigger to start
2 - to coil + temporarily for starting
Removed both wires immediately after starting. Engine ran fairly rough afterwards but put this down to flooding during start attempts.
After getting home, I still couldn't start on key reliably, maybe 1:10 attempts to start were successful. Starter fires slowly but no run.
1 - Installed new Ignition switch, re-fitted Neutral Safety Switch connectors.
2 - Installed a Relay bypass to the starter motor: looking good initially with strong starting but then when got warmer returned to the same symptoms.
Testing on the Coil, I found + got 12 volts at RUN but dropped to 0 volts on START.
Doing some research, found the advice to bridge the connectors at the Ignition switch: I hadnt read this one 20 years ago when i first installed the Electronic Ignition! :) So have been happily running for this time without.
Then read some (AI provided) advice about running a secondary wire from Starter motor second spade connector around the Coil +. On Start, 12 volts runs from this spade connector to Coil + via the Starter Solenoid, tested this and starts very strongly at the first turn of the key! Great.
Apparently this was used in later H series to boost starting?
My question is: Is this a valid and safe change? Or have i just masked the symptoms of a failing Coil or something else from a well running 20 year old setup?
I dont want to band-aid an issue that will bite us later.
|
|
|
|
|
|
Rank: Veteran
Groups: Moderator, Registered, Veteran
Joined: 1/03/2005(UTC)
Posts: 14,957
Thanks: 1 times
Was thanked: 573 time(s) in 545 post(s)
|
All you need to do is put it back to original, and bridge the START and RUN pins on the ignition switch. This way the coil always get 12V. You may also have a tired component or two.  |
_______________________________________________________
If we all had the same (good) taste, who would buy all the Fords? |
 1 user thanked HK1837 for this useful post.
|
|
|
|
Rank: Newbie
Groups: Registered
Joined: 25/03/2025(UTC) Posts: 2 ![Australia]( "Australia") Location: Melbourne Thanks: 2 times
|
Originally Posted by: HK1837  All you need to do is put it back to original, and bridge the START and RUN pins on the ignition switch. This way the coil always get 12V. You may also have a tired component or two. Thanks HK1837, its looks like you've used copper wire here. I dont have this and soldering such a short piece of stranded wire is difficult without it self-destructing. Would it be acceptable to use a nail or similar? I have plenty of nails...
|
|
|
|
|
|
Rank: Veteran
Groups: Moderator, Registered, Veteran
Joined: 1/03/2005(UTC)
Posts: 14,957
Thanks: 1 times
Was thanked: 573 time(s) in 545 post(s)
|
Originally Posted by: JackC Originally Posted by: HK1837 All you need to do is put it back to original, and bridge the START and RUN pins on the ignition switch. This way the coil always get 12V. You may also have a tired component or two. Thanks HK1837, its looks like you've used copper wire here. I dont have this and soldering such a short piece of stranded wire is difficult without it self-destructing. Would it be acceptable to use a nail or similar? I have plenty of nails... Its just copper 1.5sqmm building wire with the insulation removed. You can buy it at Bunnings. It won't self destruct. I soldered that with a standard soldering iron. Don't use a nail unless its a copper nail, you need copper. I kept the original ignition switch out of the car though (its a HJ Premier with 108,000kM on it), and bought a Rare Spares one to solder. |
_______________________________________________________
If we all had the same (good) taste, who would buy all the Fords? |
1 user thanked HK1837 for this useful post.
|
|
|
|
Fastlane
»
Holden Forums
»
Holden Technical Talk
»
HQ 72 - Electronic Distributor - Running a 'booster' from Starter to Coil + for better starting?
Forum Jump
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.
